The present invention relates to a safety device for linking reference grounds and analog reference voltages in integrated circuits, especially in electronic motor vehicle control systems, with an interface for connection of external circuit branches, e.g. adjusting and sensor systems, with a power supply network conducting a supply voltage derived from a main voltage and a common ground conductor. It also relates to an improved electronic motor vehicle control system including this safety device.
The control system in its entirety must not fail in the event of short circuits, especially at the battery voltage, particularly because of safety reasons, in connections of sensors and actuators with an electronic system in a motor vehicle. This is especially true for connection of reference grounds in hybrid circuits, micro-hybrid circuits or circuits of other substrate technologies. Failure of the entire ground branch of the reference grounds because of a short circuit to the battery voltage can occur in the known motor vehicle control systems.